A function of some types of footwear is to protect the foot sole of a wearer against penetration of nails, screws or other similar sharp and rigid objects through the sole of such footwear when the wearer steps on such items. Accordingly, some items of footwear include a sole protection.
In some items of footwear, sole protection is provided by a steel or like puncture resistant material as an insert or embedded into the sole of the item of footwear. More recently, non-metallic multi-layers puncture resistant insole board as also been developed, to provide more flexibility and insulation. According to some protective footwear standards, the steel or like puncture resistant material, where incorporated into the footwear, shall cover a minimal area of the sole, including the front and heel area, and shall be an integrated part of the footwear.
Referring to FIG. 1A, an item of footwear with sole protection is illustrated at 1 in accordance with the prior art. The item of footwear 1 has two parts: the upper illustrated at 2 and the sole 3 secured to the upper 2. A junction 4 between the upper 2 and the sole 3 defines an inner perimeter 5 of the item of footwear 1. The sole 3 includes an insole structure 6, a midsole structure 7 and an outsole 8. The sole protection is provided by an insole board 9 made of multi-layers puncture resistant laminated fabric.
However, the item of footwear illustrated in FIG. 1A is still subject to penetration of sharp and rigid objects through the sole 3 into the upper 2, adjacent the inner perimeter 5 of the item of footwear 1 defined about the junction 4 between the upper 2 and the sole 3, as illustrated by penetrating objects in FIG. 1B.